1. Field of the Invention
The present invention generally relates to a backlight module, in particular, to a direct-type backlight module having an edge-type light emitting structure.
2. Description of Related Art
As a liquid crystal display (LCD) panel does not emit lights itself, a backlight module is required to provide a sufficient intensity and evenly distributed light source to display an image. A structure of a conventional backlight module mainly includes two types, namely, an edge-type backlight module and a direct-type backlight module.
In the edge-type backlight module, a light source is placed at certain edges around the light guide plate, and then the lights are guided, so as to provide uniform light emission, which is edge-type light emission. As the space at the edges is somewhat limited, the numbers of cold cathode fluorescent lamps (CCFLs) or light emitting diode (LED) light bars capable of being arranged therein to provide a light source is restricted. Thus, if the edge-type backlight module is used in a large-scale display, a phenomenon of insufficient luminance occurs, which fails to satisfy the demand of a high brightness. In the direct-type backlight module, a light source is disposed below a LCD panel directly, which is upward-type light emission. Although this type of backlight module provides sufficient backlight brightness, the evenness of the light provided thereby is poor. Therefore, a large light source diffusion space is further needed and the structure of the backlight module is rather thick, such that the thin-type design thereof cannot be realized.